This invention generally relates to printer apparatus and methods and more particularly relates to a printer and method for printing indicia on a disk, such that printing speed is increased and printing costs are reduced.
Compact disks are generally of two types. One types of compact disk is commonly referred to as a recordable compact disk, which is insertable into a compact disk recorder. A user then records digital data onto the compact disk by means of an input device, such as a computer connected to the recorder. The recordation is typically performed using laser light impulses that "burn" the digital data into the recordable disk in binary code. This digital data may then be optically read by a suitable compact disk player. Thus, the recordable compact disk allows the user to write data onto the disk. Another type of compact disk is commonly referred to as a read-only memory compact disk, which has the digital data already "burned" into the disk when received by the user. In this case, the user may only read the digital data by means of the compact disk player and may not write data onto the disk. Recordable and read-only memory compact disks are becoming more prevalent due to their lower cost, compact size and easier data retrieval compared, for example, to magnetic data storage.
In any case, it is important to label the compact disk for the purpose of identifying the data content of the disk. Such identification facilitates archiving of a plurality of disks having different data content and also facilitates distribution of large data files. This labeling may be obtained in several ways. For example, read-only memory compact disks are typically labeled using a silk-screen printing process because read-only memory compact disks are usually mass produced and silk-screen printing is particularly suitable for mass produced articles. Printing on recordable compact disks, on the other hand, is typically produced by manually writing identification information on a label and attaching the label to the disk or by using a felt-tip stylus to write directly on the surface of the disk itself. However, with respect to the silk-screen process, rapid change-over to print different label information on different compact disks is not readily possible thereby resulting in an inflexible manufacturing process. Of course, manually writing identification information on the disk is time-consuming and thereby costly.
A method of printing label information on a disk is disclosed in U.S. Pat. No. 5,317,337 titled "Printing Method For Disc-Shaped Information Carriers" issued May 31, 1994 in the name of Helmut Ewaldt. This patent discloses a data-processing system including a printer head movable radially over an annular area of a disc-shaped information carrier to print in the annular area The printer head prints a radial line label information starting at an inner edge of the annular area up to an outer edge of the area. After the line is printed, the disc-shaped information carrier is rotated through a given angle whereupon another radial line of label information is printed. This process is continued until the information carrier has made one full revolution and the entire annular area has been printed. Printing is controlled by a printing program in a data-processing system, which also supplies the label information. However, the Ewaldt device is relatively slow in printing because the Ewaldt device uses but a single printer head. Moreover, if an individual printing element in the printer head malfunctions, the entire printer head must be replaced if quality printing is to be maintained. Replacement of the entire printer head increases printing costs.
Therefore, there remains a need to provide a printer and method for printing indicia on a disk, such that printing speed is increased and printing costs are reduced.